This proposal represents a five-year curriculum and research plan designed to transition the candidate to an independent investigator in clinical research. During the five years the candidate will complete coursework relevant to the project and will execute the research plan. Infection is one of the leading causes of morbidity and mortality in residents of long-term care facilities (LTCFs). As a result, LTCF residents are exposed to large numbers of antimicrobial agents but use of antimicrobials in LTCF residents is often suboptimal due to difficulty in distinguishing acute infection from colonization and due to the increased likelihood of inaccurate or inappropriate antibiotic prescribing in LTCF residents (for example due to increased presence of antimicrobial resistance). The emergency department (ED) is a common site for treatment of infection in LTCF residents, particularly those most severely ill. Comprehensive programs to address problems of antimicrobial use for LTCF residents in the ED are currently lacking. The conceptual framework for the study is borrowed from the literature on antimicrobial stewardship programs (ASPs), empiric antibiotic treatment, and LTCF infection control guidelines. ASPs have been successfully implemented in inpatient populations to improve antimicrobial prescribing practices and outcomes with resulting decreases in resistance and side effects. This study expands their use to a high-risk ED population with the goal of incorporating both improved diagnostic accuracy and empiric antimicrobial prescribing. Current LTCF infection control guidelines recommend that acute infection be diagnosed in LTCF patients only when they meet specific criteria in order to differentiate active infection from colonization and prevent overuse of antibiotics. These guidelines were developed for use in the LTCFs themselves and have not yet been studied in the ED or inpatient settings. As failure to differentiate acute infection from colonization in the ED may lead to inappropriate antibiotic use, validating diagnostic guidelines in the ED setting is an important step towards appropriate antimicrobial stewardship. Another key concept of these studies is efficiency, driven primarily by Health Information Technology (HIT). In an era of limited resources utilizing pre-existing HIT systems and information will allow extension of ASPs to novel clinical settings and populations. The majority of moderately- to severely-ill LTCF patients receive their initial diagnosis and initiation of antimicrobials in the ED. To improve care of this high-risk population, our overall objective is to develop and implement an antimicrobial stewardship program (ASP) based on use of health information technology (HIT) for ED LTCF patients that will result in improvements both in accuracy of diagnosis and in correct antimicrobial prescribing. To achieve this objective, we will conduct two projects with the following Specific Aims: Specific Aim 1 (ED-observational): To develop a validated definition for acute infection and to identify antimicrobial stewardship needs in ED LTCF patients. Specific Aim 2 (ED-interventional): To test the effect of implementing a health information technology (HIT)-based ASP for ED-LTCF patients on diagnosis and treatment of acute infection. For Specific Aim 1, the project (SA1: ED-observational) will consist of a prospective observational cohort study of ED LTCF patients. It will be used to validate definitions for the presence of acute infection in ED LTCF patients (as distinct from colonization), establish baseline rates of need for ASP interventions, and develop data required to construct specific antimicrobial recommendations and an ASP for ED LTCF patients. For Specific Aim 2, a prospective, interventional trial (SA 2: ED-interventional) will be conducted in which an ASP program tailored to ED LTCF patients will be devised and implemented. This phase will rely on the use of a real-time web-based health information technology (HIT) decision support tool to provide the intervention. It will include factors such as the suggested algorithms for diagnosing an acute infection in LTCF patients, a newly developed antibiotic by site grid, patient specific past culture results, patient specific data on hepatic and renal function with recommended dosing, and formulary restrictions. Outcomes will include accuracy of diagnosis, appropriateness of empiric antibiotics, and ongoing requirements for ASP intervention. The career development plan will include didactic work in advanced biostatistical techniques useful in conducting these studies. Coursework will also be undertaken in specific aspects of aging studying biology of aging and challenges in aging research. It will also include a significant component studying the application of health information technology including didactic coursework, online coursework, and practical experience to allow completion of the proposed research and position the candidate for further studies. Based on the results achieved, it will be possible to develop validated and reproducible interventions to improve antimicrobial stewardship in a variety of settings. The proposed projects and career development plan will provide an important initial step towards the ultimate goal of improving care for residents of LTCFs.